PK Generation and FrontBase

Hi all,

I’m trying to find a solution for the (temporary ?) lack of horizontal inheritance so I did model vertical inheritance following :

https://cayenne.apache.org/docs/3.0/modeling-vertical-inheritance.html

using a Frontbase database.

I did :
- create the model,
- generate the database,
- fix lack of jars and other things like username, password, jdbc driver

The demo code below starts well and connects to database...

try {
ServerRuntime cayenneRuntime = ServerRuntime.builder()
.addConfig("cayenne-CayenneTest.xml")
.build();

ObjectContext context = cayenneRuntime.newContext();

Book _newBook = context.newObject(Book.class);
_newBook.setTitle("Nouveau Book");
_newBook.setCreated(new Date());

context.commitChanges();

EBook _newEBook = context.newObject(EBook.class);
_newEBook.setTitle("Nouveau EBook");
_newEBook.setCreated(new Date());
_newEBook.setDownloadUrl("https://www.google.fr/");

context.commitChanges();

PaperBook _newPaperBook = context.newObject(PaperBook.class);
_newPaperBook.setTitle("Nouveau PaperBook");
_newPaperBook.setCreated(new Date());
_newPaperBook.setShippingWeight(1000);

context.commitChanges();

List<Book> _books = ObjectSelect.query(Book.class).select(context);

System.out.println("** ALL **");

for (Book currentBook : _books)
{
System.out.println(currentBook.getTitle() + " created on " + currentBook.getCreated());
}
}
catch (Exception e) {
System.out.println("An error occured : " + e.getMessage());
e.printStackTrace();
}

…but throws this exception

An error occured : [v.4.1 Jul 14 2020 10:40:45] Commit Exception
org.apache.cayenne.CayenneRuntimeException: [v.4.1 Jul 14 2020 10:40:45] Commit Exception
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:774)
at org.apache.cayenne.access.DataContext.commitChanges(DataContext.java:691)
at your.app.Application.<init>(Application.java:50)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at com.webobjects.appserver.WOApplication.main(WOApplication.java:547)
at your.app.Application.main(Application.java:25)
Caused by: java.lang.NullPointerException
at org.apache.cayenne.access.jdbc.SQLTemplateAction.execute(SQLTemplateAction.java:242)
at org.apache.cayenne.access.jdbc.SQLTemplateAction.runWithNamedParametersBatch(SQLTemplateAction.java:179)
at org.apache.cayenne.access.jdbc.SQLTemplateAction.performAction(SQLTemplateAction.java:111)
at org.apache.cayenne.access.DataNodeQueryAction.runQuery(DataNodeQueryAction.java:97)
at org.apache.cayenne.access.DataNode.performQueries(DataNode.java:273)
at org.apache.cayenne.dba.frontbase.FrontBasePkGenerator.longPkFromDatabase(FrontBasePkGenerator.java:143)
at org.apache.cayenne.dba.JdbcPkGenerator.generatePk(JdbcPkGenerator.java:220)
at org.apache.cayenne.access.DataDomainInsertBucket.createPermIds(DataDomainInsertBucket.java:168)
at org.apache.cayenne.access.DataDomainInsertBucket.appendQueriesInternal(DataDomainInsertBucket.java:76)
at org.apache.cayenne.access.DataDomainSyncBucket.appendQueries(DataDomainSyncBucket.java:78)
at org.apache.cayenne.access.DataDomainFlushAction.preprocess(DataDomainFlushAction.java:185)
at org.apache.cayenne.access.DataDomainFlushAction.flush(DataDomainFlushAction.java:143)
at org.apache.cayenne.access.DataDomain.onSyncFlush(DataDomain.java:624)
at org.apache.cayenne.access.DataDomain.onSyncNoFilters(DataDomain.java:594)
at org.apache.cayenne.access.DataDomain$DataDomainSyncFilterChain.onSync(DataDomain.java:822)
at org.apache.cayenne.tx.TransactionFilter.lambda$onSync$0(TransactionFilter.java:61)
at org.apache.cayenne.tx.DefaultTransactionManager$BaseTransactionHandler.performInTransaction(DefaultTransactionManager.java:183)
at org.apache.cayenne.tx.DefaultTransactionManager$BaseTransactionHandler.performInNewTransaction(DefaultTransactionManager.java:155)
at org.apache.cayenne.tx.DefaultTransactionManager$NestedTransactionHandler.handle(DefaultTransactionManager.java:98)
at org.apache.cayenne.tx.DefaultTransactionManager.performInTransaction(DefaultTransactionManager.java:65)
at org.apache.cayenne.tx.DefaultTransactionManager.performInTransaction(DefaultTransactionManager.java:43)
at org.apache.cayenne.tx.TransactionFilter.onSync(TransactionFilter.java:61)
at org.apache.cayenne.access.DataDomain$DataDomainSyncFilterChain.onSync(DataDomain.java:821)
at org.apache.cayenne.access.DataDomain.onSync(DataDomain.java:581)
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:742)
... 9 more

It seem’s to be related to pk generation so I try a select unqiue from Book in FrontBase and it worked lije a charm.

Any idea ?

Many thank’s,

Jérémy